[MERGED PR] Wraith salt rework

[LeahTheTech]

I'm hoping the line of sight blocking won't be tooo too strong because wraiths have the advantage of being able to approach from all angles and there's always going to be people moving around, leaving the circles, scuffing them etc. The salt also has no effect on wraith summons, animated objects etc who can easily walk/float in and cause chaos.
Definitely open to rebalancing it if it turns out to be too annoying though.